Snap switch



oct. 2'5, 193s. .y c. AALBORG 2,134,541

SNAP SWITCH Filed 0G11. 2l, 1936 righ/- Patented oct. 25, 193s PArsNr 'sorrise i Christiani Aalborg, Spring-field, Massi, assignor to Westinghouse Electric & Manufacturing Company,East Pittsburgh, Pa., a corporation of Pennsylvania Application OctoberV 241,

1936,- fserial No. 106,785

' s claims. (c1. zooi-'sei` My invention relates' generally to switch mechanisms and is directed more particularly to switch mechanismsin which movement of an operating member causes a blade of the switch to be rotated 1 over a series of stationary switch contacts with a snap action. e

' `An object of the invention is to provide an imp-roved switch mechanism of this general type.

` Another object of the invention is to provide an improved switch mechanism of vthe snap-acting type which is of simple and rugged construction, which requires a minimum number of parts, "and which can be manufactured at a relatively low istic of my invention are set forth with particular-` l drawing, in which:

cost.

The novel features that'l consider characterity in the appended claims. The invention itself, however, vbothas to structure and operation, together with additional objects and advantages thereof, will best be understood from the ,following detailed description of a specific embodiment When read in connection with the-accompanying Figure 1 is a plan view of a snap switch em-f bodyingthe features` of my invention with they operating member thereof removed;

`Fig. 2 is a vertical sectional View of the snapswitch illustrated in Fig. 1 with the operating` membermounted in position thereon, taken on theline 1li- II of Fig. 1; r l Fig. 3 is a top plan View of the operating memf ber`for the snap switch illustrated in Figs. 1 and ing member illustrated inFig. 3.

2; and

Fig. 4 is a front elevational view of the operat- Referring no-w to the drawing, the structure of the snap switch embodying the features of my invention consists in general of a base 5, a plurality of stationary contacts 1, a notched latch p late 9, a switch bladel I, an actuating spring and a manually controlledoperating member I5.v

The base 5, which is constructed of suitable insulating material, has disposed in .openingstherea plurality of spaced contacts 1 arranged in an arcfof a circle.` Each contact is provided with a terminal connector I1, which has an 'opening provided therein for receiving a reduced portion i9 of the contact member 1. The contactl members and terminal connectors are each secured to the base by `means of the reduced portion 19 thereof` which passes through the opening provided in the base, and has its end portion spun over against a' washer 21| positioned between-the end of thereduoedportion and-the base. `Each terminal con-Vv nector; His; provided `withffapair of clampfpor-U tions, one clamp portion 23 adapted to receive a conductor wire 25,- and the other portion 21 adapted to receive the insulation 29 surrounding the wire.

A spindle 3l is mounted on the base approximatelyat the center of the arc of the circle along Which the contacts are mounted. The spindle is providedwith a reduced portion 33 which passes through an opening provided in the base, and has its end spun over against a washer 35 on the under side of thebase. The latch plate 9 is provided with an opening for. receiving the reduced portion 33 of the-spindle 3l, so that the latch plate is held in rigid position between the shoulder ,onthe' spindleand vthe base 5. The latch plate 9,1 has a segmental portion 31 provided with a flange 39. The ilange 39 has a plurality of spaced notches 4I, one for each contact. f Each notch is located at a point diametrically opposite its coresponding stationary contact. The latch plate 9 has an extension 43 provided with an opening at the end thereof for receiving a terminal stud 45. The terminal stud passes through a terminal connector 41 similarto the connectors I1. The terminal connector 41 .is adapted to receive a live conductor 49 provided with an insulating sheath I.

The terminal connector 41, terminal stud 45, and extension 43 constitute a means for conducting current from the live conductor 49 to a switch blade, which will now be described. The switchv blade ll is constructed of suitable resilient conducting material and has a longitudinal opening 53 adjacent the center thereof for receiving the spindle 3|. The forward end of theswitch blade l I is provided with a hanged head 55 adapted to*l adjacent the slotted opening 53, and a second pair of similarly spaced projections 3i extend upwardly from the opposite edge of the switch blade adjacent the slotted opening. The switch blade is mounted on the spindle by means of the slotted opening 53 and is held in spaced relation from --the base 5 by means of a spacer washer 63. The slot 53 permits the bladeY Il to have a limited sliding' movement and to rotate for successive engagement with the spaced contacts 1.

Spring means i3 is coiled aboutl the spindle and the free ends 65 thereof extend' through the space between theprojections 59 andi, as shownin Fig. 1. The normal tension of the spring causes its projecting ends 65 to engage the rearward projections 6) and 6I, so as to bias the blade in a longitudinal direction to cause the latch projection 59 to engage in one of the notches 4I so as to lock the switch blade I I whenever it engages any of the stationary contacts I.

j member I5 in which sucient tension An operating member I5 of molded insulating material is rotatably mountedV on the spindle 3I and is held thereon by means of a split'ring 61 so that the spring I3 is compressed to press the switch blade I I into engagement with theY contacts I and to hold the blade against the spacer 63.

The operating member I5 is of segmentalshape and has a hub portion 69 formed integral therewith on the under side thereof. The hub portion is provided with a centrally disposedlv opening 'FIT by means of which the operating member is rotatably mounted on the spindle 3|. The centrally disposed opening 'II- o'pens in-to achamber 13 at the top of the operating member for receiving the split ring 67. The under side' of the hub B9 has a semi-circular flange 'I5 formed integralv therewith. One end of. the ilange 751 has a depending portion 'I1 adapted toengage the lower free end 65 of the coil spring I3- whenr the'operating member is rotated in acounter-clockwise direction. The other end of the ange'l5 is adapted to engage the upper free endy 65 of the spring It! when the operating member isrotated' in. a clockwise direction. A knob projection 'I9 is formedv integral` with the operating member adjacent the edge thereof by mea-nsf of which the operating member may be manually rotated. The operatingy member may be constructed of any suitable insulating material.

The operation of the structure described above will now be briefly explained. Let itV be assumed that it is desired to movethe switch'. blade from the position shown in Fig. 1 intoV engagement with the next lower contact. It will benoted that in the position of the parts illustrated in Fig. 1 the ends-of the spring I3 engage the' rearward projections and 6 I to' hold the latch projection 59 in one of the notches 4I so that the blade II is held in locked position on thecenter stationary contact 1f. The operator grasps the knob, IS- and rotates the operating member in a clockwisey direction about thespindle 3'I. The upper end of the iiange I5 (see Fig. 1-) engages andA moves the upper freel end of the*y spring I 3 and introduces an additional tension. in' said spring. After a slight rotation ofthe operating is introduced in thev spring means, the end of the flange causes the free upper end 65 ofv they spring to engage the forwardl projection 60. A slight additionalrotation of the operatingk member causes the upper free end of the springy to move the forward projection 60 to slide the blade longitudinally in theforward direction soV as to'- withdraw the latch projection 59-from its engagement in the notch 4-I. The switch blade is now free torotate, and' the increased tension'of the spring causes the lower free end 65 to exert considerable force on the'rear projection BI, thus causing the blade to. rotate with a snap action, so as to engage the lowermost stationary contact. 1. Further movement of the blade is prevented by reason of the lower free end 65 of thel spring engaging the depending projectionY I1 oiA the flange I5 upon the operating member I5. At this time, the normal tension of the spring moves the blade longitudinally so that the. latchV projection engages in the notch 4I corresponding to the lowermost contact. The blade is now securely locked in position on the lowermost Contact 'I. If it is desired to rotate the blade back to the position shown in Fig. 1 in which it engages the center stationary contact 'I, the operating member is moved in a counter-clockwise direction and av reverse action takes place. The projection T'Iof the flange 'I5 engages andr moves the lower i free end 65 of the spring I3 and introduces an additional tension therein. After the spring has been. tensioned sufficiently, further movement causes the lower free end of the spring to engage the' forward' projection II and move the blade longitudinally to: Withdraw the latch projection 59 from the, notch 4I in which it is engaged. The blade is now rotated with a snap action by the'tension of the'spri-ng I3 into engagement with the center stationary contact 'I. Further rotation of the-switch blade I I is prevented by reason of the upper. free end (i5-ofl the spring engaging the upper end. of theflange 15. The normalV tension of. the spring: 65. now movesthe switch blade longitudinally so that the latch projectionengages-in the notch 4Ir corresponding to the cen-A ter contact 'I. It will be noted that the engagement-of either end of the spring I-3 with the forward. projections of the pairs 60 and 6I causes sliding movement of the switch blade II so as to release the projection 59 from the notch in which it is engaged. The rearward projections of the pairs BEL and- 6I form the means by Which the bladeis rotated by the tension of the spring I3, and in addition form the means whereby the normal tension of thejspring` causes` longitudinal movement of the blade to latch engaging position; v

It is evident without further explanation that if the operating member Iiisrotated far enoughl in either. direction,` the blade will be rotated in the manner described from contact toy contact so that the amount of movement of the operating member I5 determines the amount of movement of the switchblade I'I-.

The normal` or open circuit position of the switch blade IfI is that position inwhich it engages the terminal stud 45. vIf desired, however, an additionall blank Contact and a notch therefor in the latch plate- (not shown) to be engaged by the switch blade in the'normal or open. circuit position thereof.

The number of stationary contacts and coop.- erating .notches in the latch plate may be increasedin number tozmeet the particular requirements. Only three-have been illustrated in order to simplify the drawing.

'Iheswitch mechanism described herein may,

for example, beemployed to control the motor ofV an. electric food mixing.` device, or may be employedy to control. any electrical device with which it is desirable or necessary to use a multi-contact switch having a snap action.

From the foregoing description, it is evident that the invention provides a novel form of snap switch in which a single spring serves to rotatably couple the switch blade with the manually controlled operating member, and also servesto lock or unlockA the switch blade in or from engagement with any of the contacts. The spri-ng also functions to rotate the blade with a snap action and presses the blade into engagement with the contacts;

While a particular embodiment of the inven tion has been shown, it is obvious that various changesma'y be made in the structure Without may be providedy departing from'.` the spirit "i theA invention. ForV ber may be substituted for thespecic coupling means illustrated. For example, the free ends of the spring may pass through slots in upwardly extending projection provided on opposite sides of the switch blade VI l. Various other forms of spring means. may be `used in place of the coil spring illustrated. For example, a flat `spring strip may be held in tension between the spindle 3| and the rearward projections on the switch blade.

While a preferred form of the invention has been illustrated, it is obvious that various changes and modifications, in addition to those suggested above, may be made without departing from the spirit of the invention as set forth in the following claims.

I claim as rnyinvention:

1. A snap switch comprising a base provided with spaced contacts insulated therefrom, a spindlecarried by said base, a latch plate carried by said base provided with spaced notches one for each contact, a switch blade rotatably mounted on said spindle for cooperative engagement with said contacts, a latch piece carried by said i blade for engagement in said notches, said blade `having limited longitudinal movement, a pair of spaced projections extending from each edge of said blade adjacent said spindle, a spring lmeans held in tension between saidV spindle and two opposite projections for biasing said blade and latch piece longitudinally in a direction to engage said latch piece in said notches, an operating member rotatable onsaid spindle provided with projections on opposite sides of said spindle for engaging and moving either end of said spring means to further tension the same and for causing said spring means to engage and move either of the remaining projectionsto move said blade longitudinally for withdrawing said latch piece from said 'notches when said spring has been tensioned sufficiently to rotate saidblade with a snap action.

2.7A snap switch comprising a base provided Vwith spaced contacts and a latch plate having a plurality of spaced notches, a switch blade mounted on said base for rotation to successively engage said contacts and provided with a latch piece positionable in said notches to lock said blade in engagement with any of said contacts, said blade having vlimited longitudinal movement to permit withdrawal of said latch piece from said notches, a spring means vfor, rotating said blade and for normally biasing said blade to cause engagement of said latch piece in said notches, an operating member forfurther ten- Y sioning said spring means, said spring means when sufficiently tensionedto rotate said blade with a snap action engaginga means provided on said blade to move the same longitudinally to withdraw said latch `piece .from said notches to allow rotation of said blade.

3. In a switch mechanism, the combination of a base provided with spaced contacts and corresponding stops, a switch blade mounted on said base for limited sliding movement and for rotation to engage said contacts, a member carried by said blade for engagement with said stops Vto withdraw said member from the stop with which it is engaged tofree said blade for` rotation by said spring means. Y

4. In a switch mechanism, the combination of toI .lockl said bladeiwl'ienever it engages anyY of a base provided with spaced contacts insulated therefrom and with corresponding spaced stops one for each contact, a spindle, a switch blade mounted on said spindle for limited longitudinal movement and for rotation to successively engage said contacts, spaced projections carried. by said blade at each side of said spindle, a member carried by said blade for engaging said stops to lock said blade onA any one of said contacts, a spring means for rotating said blade, normally cooperating with said spindle and one pair of said projections for biasing said. blade in a longitudinal direction to engage said member with said stops, an operating member having means for moving either end of said spring means to tension the same and for causing said spring means when it has been sufficiently tensioned to engage one of the other pair of projections to move said blade longitudinally to withdraw said member from the stop with which it is engaged whereby said blade is freed for rotation by said spring means.

with ,spaced notches one for each contact, aV

switch blade mounted on 'said spindle for limited longitudinal movement and for'rotation to engage said contacts, a member carried by said blade for engagement in said notches to lock said blade Whenever it engages any one of said contacts, a pair oi projections carried by the blade, spring means held in tension between said spindle and said projections for normally urging said blade in a longitudinal direction to cause engagement of said member with said notches, and for rotating said blade when said spring means is tensioned, a second pair of projections carried by said blade adapted to'be engaged by said spring means when suiciently tensioned to cause said blade to move longitudinally to withdraw said member from the notch in which it is engaged, and operating means for tensioning said spring means.

6. In a switch mechanism, the combination of a base provided with spaced contacts and with corresponding spaced stops, one for each contact, a spindle, a switch blade mounted on said spindle for limited longitudinal movement and for rotation to engage said contacts, a locking projection carried by said blade for engaging with said stops to lock said blade on any one of said contacts, spaced projections carried by saidV blade at each side of said spindle, a spring coiled about said spindle and having its ends disposedv said' spring; Whenrit has: been'suicientlyw ten,- sioned, to, engageone of. the other two. projections to; move saidi blade longitudinally andl WithdrawV said locking projection from the stopv with blade .withi a. snapA action in the direction of rotation of; said.r operating member,y said means of said operating; member limiting rotation of said blade an amount correspondingV to the amount of rotationof said operating member.

- CHRISTIAN AALBORG. 

